Microstrip oscillator circuits typically exhibit a high degree of sensitivity to changes in the surrounding environment causing them to become microphonic. Because of the problem with microphonics and other types of interference, stripline resonators are often used instead of microstrip resonators when designing oscillator circuits since they are self-shielding due to their dual ground plane architecture. The tradeoffs the designer faces when choosing a stripline rather than a microstrip are lower Q and higher capacitance. The lower Q and higher capacitance exhibited by the stripline causes the tuning range of the oscillator circuit incorporating the stripline to be reduced, as compared to when using a microstrip resonator.
Another problem which is encountered when designing oscillators using microstrip or striplines is that they take up valuable space on the oscillator's circuit board. A need thus exists for a microstrip assembly which retains the higher Q's associated with microstrip structures and provides the additional shielding against interference and microphonics found in stripline structures, as well as minimizes the amount of board area required to implement the microstrip.